1. Field of the Invention
The invention relates to an assembly of a drive shaft with the cutting head hub of a submersible granulator according to the preamble of the main claim.
2. Description of Related Art
Self-aligning cutting head hubs for the assembly of the cutting head hub with a drive shaft are known, whereby the self-aligning hub enables the knife blades of the cutting head disc to assume an optimal parallel arrangement with respect to the counteredges or to the extrusion-nozzle plates.
In the arrangement according to DE 196 42 389 A1, inserted into the cutting head disc is a hub that can adjust itself with respect to the plane of the cutting head disc, so that the possibility thereby exists of the plane of the cutting disc head assuming a slightly angular position relative to the axis of the drive shaft.
A disadvantage of this known construction is the fact that the hub is integrated into the cutting disc head, so that for each (possibly differently sized) cutting head the additional fitting of the costly hub and of the components that enable its movement is necessary, that is to say, the cutting head disc represents a relatively expensive, multi-part component.
In order to avoid this disadvantage, in an arrangement (FIG. 3) that has become generally known in practice, it is proposed that a connection hood 25 be applied to the actual drive shaft 1, which hood displays at its outermost end an outer thread that can engage an inner thread provided on the cutting head disc, so that thereby a simple fastening of the cutting head disc to the connection hood 25 is possible.
The connection hood 25 itself is supported in a pivoting manner and transmits the contact pressure of the drive shaft 1, via a spherical end 30 provided on the drive shaft 1, to a corresponding bearing on the inside of the connection hood 25. The drive shaft is driven in a rotating manner and entrains the connection hood 25 in the direction of rotation by means a groove-ball connection 27/28.
Due to this drive connection between the drive shaft and the connection hood, this known construction possesses the disadvantage that large forces must here be transmitted by the two balls. The processing of the bearing for the spherical ends in the connection hood 25 is expensive; in addition, at the spot where the greatest forces are transmitted, there exists for technical reasons a turned recess 29 where no force can be transmitted, and over time a troublesome edge forms on the ball.